SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04eb1fc95fbe165bf6ae7b573f9401bea84a20c74c96c49052224c614a84a93d' 
  AND token = 'zZ2H4g/ZdaQX5NmBMRRrqNm7VnPlYQOiPAJOkh8VU0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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