SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb7771b46124c60128473b2072ed54de2e04640167053e30d3ae7b1544590574' 
  AND token = 'rNzrbfmRHuUJtA+bDjq/6BuHJ1pmKHgDkJ7z6Habg4c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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