SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a6f0df30f59c22cce0974b68e238723d6bf31a6f99ddeab01a7bb21bdb344aee' 
  AND token = 'rC9uroZn8y1YQNDZM0KM85eHSZBNZsY3bnmOs620WpM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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