SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9f0a5aa89497d25464f011bae37d24c7d9fcc383bca8ffca97274b5e14cccb36' 
  AND token = '/WWwVb2KWhingXEr/w2G9PYjo8XopPkWCX1i8alVqTQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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