SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '753202e4bc97a7f49872e45ffef76393e0680be225408b9815b60e27988a42c3' 
  AND token = '+8336vdpIMSKYpOcDK/2TgNJ6w2+5KBzTsrF6YwUXec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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