SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'adeb5a0ab3bc9f068b2149c7e3f403261fde4d9931a31d900b029aa01b88a513' 
  AND token = 'gRGRvHuYwDLT1ytlMkXqdK4JJI6s+VQmJQp4uBkSCkI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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