SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c1fb9dec83d0764a43e47c41ef0d1a6b5a94c5bf14efefafef48f3447e5c6534' 
  AND token = 'mlOXYwuCQ4X1viuyhtPbaBMp234Id6Loa+d58H4KkQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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