SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7bfbbe5bb43fa17702b05a4957c24b4dc6dc4c7e4ba45287eae55584b6d1230' 
  AND token = 'P0MmzDJWv4wQhfs/ITpmhrjanWegaDLbPTmd+SdE/zU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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