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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a70de76fd6da7737c24d83f4ad5c1a36172ffaf2ae368c674e5b682879444a99' 
  AND token = 'YUB62VcRsr5ssZVw8aq/LC0Mvrk3qQFvv34anvJHBMQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}