SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e54a07f2c7ced531fdf000d2e8820c4f7c6359fa399e66a69ad31e189886ea2' 
  AND token = '+olpvDLpbHwWvNz6x1sLK85FbIj1/XOu2YYL4qxQdQc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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