SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f5ac3b205517581025c53ca8eba899d6287225ba82388572c41ff9db681743f' 
  AND token = 'sUWv3+mm32Miv1aBPUSRuZp8gp8aXuDieLvfl5hWz3c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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