SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '946e4a197e2563cb03d3c3b205d648b0d241ab63cf4b9e59e474757b9fad08e2' 
  AND token = '6mAHse4yynMS9RTH7us2rwyGxFlyaCI6wYfHbSfHne0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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