SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3522ea07236afd92c044a73feeb117f11f802122bfd07e72d317a1170631c717' 
  AND token = 'T7H8B3n6udi6DQ0SezOa7jsBaepiUTY5uoEzIJNCoTM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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