SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '159df30061096a283ce5837c9c707a077e8437cf8adf9a7256ea2fb905f1c426' 
  AND token = 'Gmwib9ya8YbBCZW8FUIImdh9xy1BzKU+sD51TtF72+s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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