SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90552778bb19ca3e2af667f22903bdf947ce18e5f09cc3c02b06c74d85dc5fbe' 
  AND token = 'Cg99wDzWD423C1cEECMTDdCp+5OQQ4FtRULy0Y/TFTk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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