SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a8eaf1693fdc3ffe5bda6f61194cb94b0f1a9bf9168ddb63f86a21868ff9d1d' 
  AND token = 'vHDv1sw+FMrCKKqUaOuD2AvndCxhcHnAjGuwCaOBXek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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