SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac2d72796fac41ea749318b75d2664fa51d901b94200aaa7917db8bedaf92691' 
  AND token = 'PoBqokbUuX3gFFFmI0f5cNnNrjkDraho/XjDBgKOFiM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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