SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84369e980454ec90db30195ed366393aebfffb7a6b69fe83955088ecafbeebb8' 
  AND token = 'gz21axW/I9iGh69QD4lKJBAZGQupCa5GbKRvZjsie6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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