SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b764e0a8b0fd97db55f419379cd0471dc2d07b4180fb3363c718292e3750200' 
  AND token = 'IhKMdzN/Who3gKQ7GWC9nl46uI8v9/LZHviWZTfXfig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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