SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '52a58d6c2092cbc9058b29f6891940370cc5e652ec36990ff64a8d292f707e8b' 
  AND token = 'PyAjsPA/vDwQxtjqVMxO8CFojDAPf9svdgXAghVoSOw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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