SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12b3ef77b8a6dd97cc5a54c61a99b7a8c6db3ca0e80ae9fe24cb4fb11842f0a7' 
  AND token = 'LzM/EJvDtYob/YGu+hyOABm85TZ2rsQKXMpv6Prfz+Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00073

JSON explain

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