SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f7cb7bac7a0ff4ff79cf9aa0fcd932e0e5b47fa698744d6849f6ae62b62331b' 
  AND token = 'VQX4WFQm9Ygb1P/gEqXAhyr/zBBMQc7In01GRjMKKIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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