SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cad39afe3d527fb081745dca2e3caa4347921a1c12ad1cd2343b1a29a5a2a2e5' 
  AND token = '96L9KLidCCtrDeE0qK8bShLMPDAK023acwPvjF/TorI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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