SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0aa504dc7030329f485270011f87453dc1f44de236817d230eaab3f56b034f3a' 
  AND token = 'JXg0XwAVNyqeOJ4KBqPD0nN7QjxEXOyYSK1XMYkwk84=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}