SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'eefac12b512492ab446ff7c603539b4f8db3f879fd44e3161655684d4992ea24' 
  AND token = '9z59hvyVGQTD11grlcd9DNxfCxZB7f+WYr3zyGTPT1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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