SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14cc7b3ff715ec6b3c42644defbf95bf04b44e4355b595e1648c8418aab20ba9' 
  AND token = 'bDqgiRX48r0NRNtUbYUc+F2hpkW3cBRaS/lUkoOREyI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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