SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a3eea0da2c632071fd706beb83db4aac986a50412daa9f402235b3f02fce515' 
  AND token = 'LZkfuaiLYnZaUCD5nyIDzCoohoH5bkJ6kopnkiTJYFY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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