SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '307e56dacccff59f8904465549cd1639d47263ee4db479cf5da5d191ef508ce3' 
  AND token = 'KlS/89DZwsECr+kDCOgpBHjEDltI5/PeGrD/WKE8MkM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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