SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4499d40dc34b53a1dde6ffd8ef2ebf2b32e939985bf68fc66e7aab41aa4531c1' 
  AND token = 'YK5Cw6lYokHFyBI5Rxu54SupfH7CBOvBpzsPE1USSPA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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