SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '479bed8b81f3ed64ae31870e7d0bdcbfcc66141b1ab772546ec97fc61207fd43' 
  AND token = 'Ew2JLIFIvc6qXt2Dqs6grJirhkLi2kF4/LCVM3TvnM8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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