SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87dcd55bbad1640d93800123551c2e9b39759aca87b09e7513c8d4b4b0c69e1b' 
  AND token = 'wXEX9hLZYzb5u3u7R4n+/DLplb//CIsKYz/MUvLKGH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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