SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63669b76f8e0922c121194e891c286e67ef5052b32d1bbf43fdc7070de0afe42' 
  AND token = 'beUflpYzNsjNjEl9vvNhduOG1VzXI+spTaeiudueTNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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