SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '848ec9df4a5dfdd7b5a9b9572a614a0f9bb13902c7bbd2589d4273ece3738142' 
  AND token = 'NwiLzwF65kqQpZvs085y27CDRHQIFVqiQvHiiRzAEus=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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