SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '242fb3f061ee50f037ecec918d4508f5114fe8a1992764c63cb5b1eae72b943b' 
  AND token = 'lbr6vYzxTtkUoZQ8R/s2q/BNL79upz6B5wkS3T68TZo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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