SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '943c7a55fc2f7486a65a1b9a0e832c547fd1ebe87f8f37c9723c45a518f6c3d5' 
  AND token = 'Bb1WDbv3thOfVQvYywDxsrdbTlNBYJxpYXZ28DDnJHI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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