SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7804f6a47be04e316e1b017c4e09786342d4017947e761c9f3a39cb8fe2bc61' 
  AND token = 'eSNDGWuGeXKhX5AiwstRqpmxagRwgK4GGzcFvPzZFtE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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