SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e8fe9cb9afd6f51dc5688c4a0f4396fb81ecb39c7fd9b49deb6175e4610c216' 
  AND token = 'YqVvJbNtJJVsm6iL2zaCgbptSnvNKKcojbeZ+nzvqJM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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