SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '760ddead1360f22e99a3bfe6370e2dfec7eaaaf1390d34d93e771529196b14b7' 
  AND token = 'AeWPCDK8ujf2LUgIdJfBDlN0+ZZ66j74/SgplDEpbQs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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