SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '59b80b04b4cadc87e91d3d7e5e2b455bb9d775070259a1393783ee3fc2960db1' 
  AND token = 'RL3DVnYBP9JWYcAYvbQ9cmC3qUHSo/5VPfN7suwQdoc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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