SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3645f71f4e2aab7cbc5885a59dc68919be7da877488eccadc3d2ea006ae95d0a' 
  AND token = 'ahhzPJOQf71de9R5/q9f5DatdsaNwVLnddhzOGYAcAI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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