SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a73080ca4130c302dc781805fd8076b476a54d0c5f2f801c98f010986a7b332d' 
  AND token = 'XuJz4IlIoLNpdR6NfgzX3Az7SWdLjQzqY2aMeYbvzD0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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