SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e2edc6c500b824ebbbb9d64768fd71f926abc63992cc68175502eaadca9bbd1' 
  AND token = 'L+YOcmK/py1X+wtAqVmTzXvqk3tcXZ3RFC3fwobvWWM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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