SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d275be0f25d58ec7f5a5c0e3a5164ec412962cb9fcabe5313aa726e7fbab775' 
  AND token = 'KERdHgmBjDW5VHY7ukO1Qo5On2Cnu7RyaepLq1tMwIQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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