SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd926303bb114f753248fc1ba79e821ead446da95655d57926906859d5cf3c62c' 
  AND token = 'LIzt19vHsDNePvu7UIWdGocMMeMkdmr2UEnw1+b5xjA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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