SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0a3b81e372cb4934ee29332b85ba6df48d8bb9737b127156a60bac7e39ddd71' 
  AND token = 'vnq9CtMIycHrAPmBsbAdRVXUHbqgZf1V/eXWk8PZAz8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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