SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1785fc1e42c7eaf88774cc4ba763f8331658cdd0cb94d521a854a1f04a961870' 
  AND token = 'Vf8MnZpVfeJKcRYKC8VEe4sDk3xP66cBjnrHvQUvMyw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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