SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5bd77aef314704f881c0376833caa46b5bbb784883e2892922fe95939d01c20' 
  AND token = 'OzJrG2oDqQ1iJWuSO9jGs5vkNAukX6qGzU8t5IvcZVw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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