SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '845af19e88eb8ced93713233a245aa69db962b6178c60defa719cc25efffbade' 
  AND token = 'y4C5meNubIhz3k/45h9u59uHbZHDSVDb0c65qRwwrcQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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