SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14d1bb180e80e9c830206d691df9611e2df768788e122c5b0fb0882cf343db54' 
  AND token = 'JchAr3NWssd/7cbxWdsm5/j7Worr2lx3HHcfEb/FDpc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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