SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7c29efe2e9a4e944422b73b908c6ba3bdbf4d5ce79dde8617997d76fdf40ba7' 
  AND token = 'SVmhm3bYJSrOymQNeeMIdkbDP9JX7bk8d45TFEgWUMo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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