SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ce0fdb1ec07580226dfc604087b2c5d223aaf469f847f4dc56008a6265f01f6' 
  AND token = 'aZITVEyA+f0H17Ha20dxIfDtV1i9C/wdhg4ImwTyKZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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