SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '398e658246a8cb5f6b733c62287ac4b81baa1183604f78388ea149ef450e4b95' 
  AND token = 'SOjnb884qLy3lS3Aji10PD7jzOZAQPajNsjz3zk5rxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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