SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d68df8edd2d672cc24a2938147fd1085af2903d014ee96cea69078bc7fb2ad7' 
  AND token = 'WAY8pQ4BCJWBz3osHVBYqRChmy/AzeugXDxDHeHGfCM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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