SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ae3be72553b7be0ad13871556d4ca26dba001e3df3647c8cd177474902773d4' 
  AND token = '2z6sFJQbN6kJC5O/Fl0zfPuJBbFQ2UnXbl6BrRUfVLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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