SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d665d7ac5f1084e71f2a080464eb4d5ffbc42126a9ae65f106f373a38b6f62d' 
  AND token = 'KxJroqibjtjhNlYgaA7nSZeCOzhIo3OUuKKxPkAr+LI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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