SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a882e7b950a4c497747aa5727b88974a3dc8d705db7f95adc2a80b1ca97a0b7' 
  AND token = 'hjDdtwCYkSnGiD8PzWt9Vq5ldXH6SYYxtDJJnWyPoZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}