SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a2e72a7a5270488bf07e3094df07336893f01ccac6b62bb0bea275dbb023097c' 
  AND token = '2JeWd7n5GNn9irZ+ySDXF1qBDkNN4GSRao0wLbiQqqQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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