SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74b555fb8709432f0bce47c0e068bcee18bd966c0eb18edaf6304c805b316179' 
  AND token = 'Er55JcHoyFl4nKeQcgi7j55J8c4bwrUvKHTcHkgm324=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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