SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3399497d6ea64eafa0f81bf2ede0a030ae570a061905b4d5bd4c78cf44f202a8' 
  AND token = 'XrTQnfI+2ZVXTkbXu2zfAeQsirNj2hCF9Cf0ft0lmmg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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