SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '553dc6404b5c56406fe64f38645eff06aed7e736155fa767300b9257b9fa7fef' 
  AND token = 'AsG36FftISzRPr3gOz9U6qnAXfI5ldBDuOvnT5JLOHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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