SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bf71321c3db9d343686150948e663eac99c54761f9b8305a8b58579484bdf8a2' 
  AND token = 'tIJwvhP18SAPgogG07xGWLquHLmwan+PcVh5+VHiXVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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