SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce4296a2f0e94905928cf481e62a7e82b6e2bbdaf80d225b54cb326ae78f95f8' 
  AND token = 'r8VuEr42XqFZlEk7j7vvTnjqipfoCvy2pqPlsRZfVVU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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