SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46494dbdff0c30f61e8f98b2d82f60d22215928685d26b7c8097f1805501f12d' 
  AND token = '9Ruq9Vib1lfci8LNmtZr+Y8FQdv5Qpm4Fs8UbYdABqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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