SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa59515806b4bbc31ca4c351a614872ab291eec04450633128ece5088425df42' 
  AND token = 'GVK6lwBZOY+CIRQbE0p+T9zEsi8cRT1JiARHVEGpS38=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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