SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2681759547345350a9e772b7b6d1a13ab8910d068285a22877ad877cfae14422' 
  AND token = 'g2vgRqFOyud6LOyi2fNJKn+xauRMKqWnQN/xY2ZfMZ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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