SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e593514ba46a3eaf6cff181e487d0397bc00ceae868e2b6c802ece89457caa3' 
  AND token = 'eZgLT3Evf8Ga8oHI0vGU5b6gkicYbdQtpcODick7C6c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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