SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8aa28edeeac5230052d861bcd90ca1da33a1da3b88e3ad915c4799b91c558c67' 
  AND token = 'PtElB9p8KxB7wM/0g+7+cIKS1iU9kSZ/QoRkuFqiTdY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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