SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '578b4693da6fb9978d8c0c32ef73547203752b44c685fa269a6a43d96743e98a' 
  AND token = 'Vqfhh0FkQkyN2TDDuv5coojmALCDjtdmeP+nivruhqk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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