SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9199a8729f7f7c032118f3f3548ca3f61087b41f4d1c51c91412b733cc063a7' 
  AND token = 'OBvF8Odqp+x/frTFd5YS2ZQnXo8BU2l4ksDK2VbBQAw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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