SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cef5aa988230ce8e76154a76e735594df5b697635245d90d57ce5d26028debbe' 
  AND token = 'yc09BFtDDU4rljW5NpEORcrEbs1z7Zyi9EOJYaWE3R4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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