SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3b20b732003a829c49dd40a2d49528bd079bf039c457fd3137ba24dd0a9972b' 
  AND token = 'BudY8HeoNo/N4SstNLBkhVJgak/KaK5xRfVbf6zMdr4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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