SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'feab48fe6f2bcf527b1001ae33bc3dafcb34a974a4421189ee5c6157bfe1b674' 
  AND token = 'KmZsrgZJ9Y+erac9pzKIJKMs1R+LJv7fyp2EuwaVmmM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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