SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c805e71eb7b053d75ddade8ba9e861c12aae8b3aa7818b07a6e54d2abdbba154' 
  AND token = '1/5hjrl8Lq/g0q6CJtD13+2WKjSovkuT1euVMh6MeS8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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