SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c097ae7aed4b09d13e94e65de2f56278eb0837451b7032ced8dc91e6e540116f' 
  AND token = 'Qpu6Jh7l4VXB8RnPJOtGq+dsm+Y2+mNUnsOLEUcGKW8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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