SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '30ad584b19c65a60a079f9524de31468c596645e3b8c1ef624369c326cbefe7c' 
  AND token = 'NiLOb+2mh31fu8XTv6cNw87opDQHZDj8uUvK/zwc8VE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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