SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2c1c9f322581b29ef1ccb577a1ec8a3146bc3280938a58b8a4f2ac4b9b31aab7' 
  AND token = 'MCc1BRioq8Udl7y2j4REB3YwjwjGXOTUFwCz6nqR1Ok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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