SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69a3db09a904a5582ec5645f55766a84dae968db554556b06143a3ea06a6f545' 
  AND token = 'ckMfvTvTacveHZFOhwv0oOhJAaMYSai+i+Bw157lWcg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}