SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90039acb4221056e976f5adf327bb819f343a71d03bf160d7b874f4a772f0b63' 
  AND token = 'tNWgvJ7+l5VNzj5jHkS75PaSrfPvbCXQPUDWfH64vuM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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