SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77e11d4ba61e28fc35bb05474b7263acd15de4b0c0461b9d552442d51d7f684e' 
  AND token = 'oMKGZmTS0QYmvwhVxnzcACkx2JYAvh3DOBl5JjSRePI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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