SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29ce226cb8465fe9308cc81bce4dcc73b65db267bcf2443b81d485185da13037' 
  AND token = 'kHQo2Le/EAaKfMjGI+eI2+HcfwzBU90fhZziZIerQ7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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