SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a837815c3aa90226a9dde99685820ae773004999e35f19891765ff705c3933b6' 
  AND token = 'lecHSPELryFFKjixffrX3smN7YCl6ThCYxfFt7g7tyU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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