SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abde38c4e5ec18f51ef1387c6c2437c939889090b528f76b921d09b62f2bfaf0' 
  AND token = 'Qd0Q0/nlTABWtlEAxrCixPFyEMKVQZiC1puv+B0dGQQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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