SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b614a6ff829cd5685179a101ff4cb54371e98305504214d3cdb41f68e1a9cc7' 
  AND token = '4f5fH0OVQYXvnV3SBbbsYYxkFUOYeLjVzfJLtcAQDZk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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