SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3230d787536b99a5d1da113c2da6b3cebc1819178f896700750a460aa9c5a33' 
  AND token = '9svIO5ahJUhYDEU9WykX6Veh4xBIrqDwmJhZBfjPqlM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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