SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '760f7ddfb78e7963ca5f1c185597553964c1eddaa21a8dfab64f438fc7c804d1' 
  AND token = 'hTffQe5UfHt+na8pRZ6jOj4b9EeI7ciHaoQSDmBe1Ss=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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