SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c3eb139f8f6b7ef957e7d569023ee26272a1f6ba8fc9f5bc8c48251c8ae19c3' 
  AND token = 'cbryZ6Vo5zj5fgm5Ym6c9LqCZWg1l5snpC2+KTB8J0w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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