SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6aa28fc142be9aefe19a9078c44ad2bb17673f30d9a80a60a83ce1949bf70a47' 
  AND token = 'nxVICzEjNE3ngwGFFYF+Wv9O/sqH5DfOjb/6QjAz2zE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}