SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b624902e003fa774114ac31260a3b8c9618675d363ae221a8428c541a4e8c58e' 
  AND token = 'TxF/PbAV6JYLX5xJUzzPOPnj+hIGJ3H9hmFY08Ze54w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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