SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da79267f73d9571cc120731dc190fd12cf7b9a4b48109142bcc46e055f06290c' 
  AND token = '9V9M85YDURdBVuXYK+Vmv+Snqk6+WTaeovrw/tejmiE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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