Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3ef27d2c9772104846ff95f1fc5d88b6508d7e4295830f801bf0eced34e5257' 
  AND token = 'yljwm89LObqjz4NChZiMXtdf7d9ujdhtMWDXK+Uzo6o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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