SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa6bf0f549148b170679b5200eb596ffab44bd3f316d2e122e3d3440cdb47291' 
  AND token = '15MoeTZ161iFshmxQcrc/6V9gFsJOJAVVjtYDf9FOIc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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