SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbf037084728d8d7b6f33e55514e89defbeabd7ac61311794110b8758c850424' 
  AND token = 'IXuktVr0cwZ/pM94dYn1tYwDWdLOQpKRgPBjHCIWMg4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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