SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b010d7860be4bb976ef3e8e6cceabaf73d9cd668149582532cd10e53f248b981' 
  AND token = 'nZVhc+XRKRzI6JFzccrQtm9cKgKYWUoBMjN0wREX0Lo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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