SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20702037f3ca1cc1823b900e533ab5db63448bfb6ccf35c2a26c8dc2d271af60' 
  AND token = 'AW2wRR8jAtYmEEEoIpHwVpdL+2MlwHwFbCOA88GpW+c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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