SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d452700155e5650d47aef74f4f378cf47d6f16d1444d64c176538c1d7126559' 
  AND token = 'fnuDTOZT7AmbLrMcsLBjqwFxb52yyCQre9Aip8WGcU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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