SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff7703bfc69d38e1f4a959b6abe2752343c9777fbff8ec8e78ee4e6d4c3a863b' 
  AND token = 'HWinFgsW0aoqLLP2Tv0VSZ1OLc3SFVNxGLhE1uKCYjI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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