SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67ed2aa384a5bf36d93503e911a14efc30699540df8829056f8ce319bb1d7299' 
  AND token = 'YeLxLGNbVEXBAmj8X8nxRfQhInq8+XPtF0s+m/5IajE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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