SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '84748dee56c5e021790b02d49792d3192a965efa6baf4cb3db2bca4e591630b5' 
  AND token = '1I3//0N0SGFUuozvbEw0Lrst5yjxH5gpP9YQAMRVtKk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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