SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a669fee1919ad2b79f8825989186041c58daaebb72e84b1bca42765589ced19c' 
  AND token = 'pnj+DeBNhsVNQ99yOsEbHiGltNvYGFo5zn5GUlT7Ouk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00104

JSON explain

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