SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ea33106272012a989fe9c68f6eec9cd699facb07533690a64a0e137f20d19f12' 
  AND token = 'moiFCDwq+KXARKCXuHybJ3vvEWImA66qUIFDWzwZi0o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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