SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '82156046a04ad45b80258518812fc27f2903eff9d4f73eee5170f626d35dcaaf' 
  AND token = '8ulMg2iKUtA814eoxsdPRVGIaUXrCizNN87NzY4xcQs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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