SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c02a47329e68d53fae7c11935657c81eb2463ec2078b27e69f431c28c21b6476' 
  AND token = 'luFhRlTgKiNNTIPqLkRth9kSeNN+oY0UvJWZVMPCjf4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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