SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '29cd59aa0c6aad46243a1f88e28dfd23a12fa62fce76676ca5a8530231761559' 
  AND token = 'C4dkXJoC/5l+FnZ3B0Jz/Vaf3AgbGvpah8l8SYU3Yyw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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