SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '472fa59370539599925ccf1d6ba670343238d581166b9565c3f3e327c7eaab7c' 
  AND token = 'QGetre1vL0lPcNk/zb/vPTt4jKbkN17oehSxCfq1s5A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}