SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93dd0a8c2d126ae543b70b538eb31297a2d30b8b66be2a362593326f12b94cff' 
  AND token = 'YEJGzsbz4Buy4sWtvaxJuosL43CD4aBVGv8OIyP9lKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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