SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1a4df031f6a84e832ffe6cce10a7782dc3207668b70405f6b20137a0f1a64aa' 
  AND token = 'NEJunSjtOncOUhjzONpjNhNCZe/SQecRfYKQ4EsTxNM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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