SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '982bb99c42a5975291521d43bc6bb33c088efad2c005ab422ebd3d1f3bce7250' 
  AND token = 'TjcvUFjpeR0Vmu5t6GLH0+QUaH54TGa4AKMpGiNKVGQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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