SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e194d92beb41dc7f35de0775e3f103e9362f001c900cfe8cc1010ce85d66f8e5' 
  AND token = 'LHkbF0kucklkFIqgzyi449l4A1ZZxL9Cj3/FmExh2OQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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