SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '53d3980fb546055c03824e28d4fd38e0a8651e0d290904a7844975a1aa1b804b' 
  AND token = '0adS5yqSDqOAVSFuK87bxIh/TBxf/Ngm/uc1OhTbSgM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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