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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9c485da9b79de73fad5568c58abb6aaf2c30e8fddf0629658f72af824fe64f1' 
  AND token = 'uQMhsZBCTIDOWliVA8Z5OnMtyFo1wI6oss1Azg23bb0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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