SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0742e642713d5797899ba448c9a02fe81958a87685a0ae43277eab0dcddf58c' 
  AND token = 'cAUob4rDt2P9Q9wmSY8XnacOqtoql9EY/7tGh3/eD9Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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