SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4ae1b20102dcb028d76312b151da78d1e361e124a8ccc0c426f9c69c5909cad' 
  AND token = 'E5CrP5m63N+gRIKEl/jmL5pQHW7WOCsfDSPQtJbXfWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}