SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7340c1f8edf60c329d60ac6cf86f90f981d448691bbb220548010461df8dd345' 
  AND token = 'Kakll0e0l9us9JMlaT3I0R76lNtq5c+UTxm/dBN9/Og=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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