SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d072489c9c8dae3de6a232f484f80251a8565029adeec750f839188c1e25043' 
  AND token = 'nFjkYfRPVveflIqTC1+9zVX6eumNnnxhrzekM6MoDJI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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