SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38b1c70628f59bdc29c9ff2af32f83883624b5e342af75b1ba7e20651a24055e' 
  AND token = '/nHU1P/MaaeJ9mL8mctejS2o+q8XTK8JIvPl+Bu7oX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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