SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'beb14d34340f948d1ecbf03b1c013ee19cbd9fdb7de9c4531ef40cc2aa2c3eaa' 
  AND token = 'WUYX3hWCItrFh6WWIy8PvhoHolTKmsyHvdVG/ji4up0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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