SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '35a89fbac1c15e306161cd1050ba7c6973ab61fb9a6b08486277b079890447fc' 
  AND token = 'j+CRFBu+EYFXodqBZW6zdheeOA3z2VSUjP93yqsMgXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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