SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28a382b9f472e0543f192e76a672d8953a12a0628bef5581fd05b8b92cb6269e' 
  AND token = 'tZaKxL5PFCqBUUIg/i+88Fy8ik1IF4L/8+uq/7t9V5o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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