SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '24463d7cfd365f79194a709e85c4c714cba05066c7150a2e953c88b737ef6263' 
  AND token = '/OWUS/+agcIVU8ljgkriQQQUi7qBMii//OzEyzMwnBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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