SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd683f15bd7ac68590969fa65dbe91356b5d1d9e0d41a96a0775df144d3804e7a' 
  AND token = 'OKEKwmnixahxuVkKDcFtPww8Am6ba+4HPCtTfX0Gl7c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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