SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '700699b5aef5fa077031b25e4aed4f39883b99f2847c2ba950af1a4cff9e0622' 
  AND token = 'UEoHZJOkLvyqZ8Tz2vEJhH+sQmjKwbbso5vCBLOVVsM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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