SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b4eb674561aae583cc2aa07e21cf9ed86f9ac2933e11fcd0f9f8ac452969fea' 
  AND token = 'vWmxBk99b6gB+XDliljgAkjDRJgvLtr+0/fObiMrT04=' 
  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"
    }
  }
}